The invention relates to an escalator or a moving walkway comprising at least one roller bearing which is mounted between an axle or a shaft and at least one further constructional element.
In the further description the term xe2x80x98escalatorxe2x80x99 also includes xe2x80x98moving walkwayxe2x80x99 and the term xe2x80x98stepxe2x80x99 also includes xe2x80x98moving walkway palletsxe2x80x99.
The steps of a conventional escalator are fastened to two transport chains and form together therewith an endless, circulating step belt which runs over a respective pair of transport chainwheels at each of the two ends of the escalator, wherein one transport chainwheel pair belongs to the drive station and drives and deflects the step belt, and the other chainwheel pair is part of a step belt return station. The individual steps of the step belt are each equipped with two respective front and two respective rear guide rollers, at which the steps are guided in a location, which is defined in dependence on position by guide runners and deflecting runners primarily fastened to the support construction of the escalator.
Roller bearings are used at various places in escalators, for example for mounting the transport chain drive wheels or the transport chain deflecting wheels.
There is known from JP 06144762 a use of roller bearings in guide equipment which defines the path of the rear guide rollers of escalator steps in the region of the step belt return station. The U-shaped deflecting runners are not, in that case, fixedly secured to the support construction of the escalator, but arranged to be horizontally displaceable thereat between the transport chain deflecting wheels and coupled by way of roller bearings with the axle of the transport chain deflecting wheels. This axle is displaceable transversely to the axial direction for tensioning the transport chains. Relative movement between the deflecting wheels and deflecting runners during tensioning of the transport runners is avoided by the mentioned coupling between the axle of the transport chain deflecting wheels and the U-shaped deflecting runners. An always constant movement path of the steps in the region of the step belt return is thereby guaranteed without the deflecting runners having to be manually readjusted in the case of retensioning necessitated by operationally-caused chain elongation.
The described construction has the disadvantage that in the case of a roller bearing defect extensive demounting and mounting operations are required, since the roller bearings can be removed and refitted only by longitudinal displacement to the axle end. The demand for short interruption times for rectification of every form of possible defect cannot be fulfilled with this construction.
The present invention has the object of avoiding the stated disadvantage in an escalator or a moving walkway, i.e. of enabling the exchange of a defective roller bearing in substantially reduced time.
The object of the invention is met by a construction having a divided roller bearing mounted between an axle or shaft of an escalator or moving walkway and a further constructional element, whereby the roller bearing elements are mountable and demountable in a radial direction.
Significant advantages are achieved in an escalator according to the invention if step guide equipment, which is present in the region of the step belt return station for guidance of the guide rollers mounted at the steps of the step belt, is coupled with the deflecting axle of the transport chain deflecting wheels by way of at least one divided roller bearing, whereby the correct relative position between step guide equipment and transport chain deflecting wheels is ensured at all times.
The solution according to the invention has proved particularly advantageous in the case of an escalator in which the step guide equipment is coupled by way of roller bearings with a deflecting axle, which is displaceable transversely to the axial direction thereof for tensioning of the transport chains, of the transport chain deflecting wheels, whereby readjustment of the step guide equipment after retensioning of the transport chains has been carried out is superfluous.
According to an advantageous embodiment of the escalator according to the invention each bearing housing of the roller bearing connecting the step guide equipment with the said deflecting axle consists of two differently shaped flanges which are flanged to one another at end faces oriented at right angles to the bearing axis and are connected together by screws. In that case a respective first flange is directly connected with the step guide equipment and a respective second flange is formed to be of hollow cylindrical shape and receives the entire roller bearing. After release of the screw connection between the two flanges of a bearing housing the flange of hollow cylindrical shape can be pulled off the roller bearing in axial direction so that the roller bearing is exposed for demounting.
A particularly simple axial fixing of the roller bearing, which connects the step guide equipment with the said deflecting axle, on the deflecting axle of the transport chain deflecting wheels is achieved if the inner ring halves of the roller bearings are mounted in recesses in this deflecting axle.
In advantageous manner the transport chain drive wheels are mounted by way of divided roller bearings on a stationary central axle in an escalator according to the invention. It is thereby achieved that, in installation situations where the escalator is not laterally accessible in the region of the transport chain drive wheels, the roller bearings can be drawn out of the bearing housings from the escalator inner side in direction towards the axle centre and can be remounted in reverse direction.
A particularly stable construction of a transport chain drive wheel unit results if the two transport chain drive wheels are connected together by means of a hollow shaft. The large torsional stiffness of such a hollow shaft guarantees perfect synchronism of the transport chains, and problems with worn-out shaft/hub connections of customary kind are avoided by the screw connection between hollow shaft and transport chain drive wheels of large flange diameters.
In order to be able to withdraw the roller bearings from their bearing seats in the direction of the axle centre and remove and reinstall their subsequently divided components for a roller bearing change in a transport chain drive wheel unit with a hollow shaft, a respective through-opening penetrating the cylinder wall of the hollow shaft is present in each of the two end regions of the hollow shaft.
A particularly advantageous embodiment of the invention consists in that the hollow shaft connected with the transport chain drive wheels has in its cylinder wall at least two groups of radially arranged threads with setting screws, with the help of which the hollow shaft and the transport chain drive wheels are supported on the stationary drive wheel axle before removal of the roller bearings. A roller bearing change can thus be performed without the transport chains having to be removed from the transport chain drive wheels or the latter having to be fixed by involved measures.
According to an advantageous development of the invention parallel bores are arranged in the component, which contains the bearing seat for the outer ring of a divided roller bearing, around this bearing seat, wherein a parallel, slot-shaped channel is present between each of these bores and the bearing seat. Inserted into each bore is a withdrawal device which fits therein and has at one end a form of nose which engages behind that end face of the outer ring of the roller bearing which lies more deeply in the bearing seat. The withdrawal device includes an axial thread and a withdrawal screw which co-operates therewith and which is supported by its end in the interior of the bearing seat component. Through rotation of this withdrawal screw there is effected an axial movement of the withdrawal device which in that case moves, by its nose, the outer ring out of the bearing seat.